SAN DIEGO -- Two environmental activists who refused to testify to a federal grand jury investigating an arson fire in University City were ordered jailed by a judge who found them in contempt of court, it was reported Wednesday.

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David Agranoff, 31, and Danae Kelley, 21, were told by U.S. District Court Judge Irma Gonzalez that they will be released when they agree to testify, The San Diego Union-Tribune reported.

They could be held until the grand jury term expires on Dec. 27, or longer if the term is extended, the newspaper reported.

The grand jury is looking into the Aug. 1, 2003, fire at a condominium construction project that burned to the ground, causing $50 million in damage.

Neighboring condominiums -- that were occupied -- were damaged by the extreme heat caused by the blaze.

The Earth Liberation Front took responsibility for the blaze.

Agranoff organized a speech later on the day of the fire by an activist who was also a convicted arsonist and Kelley was among several who attended, the newspaper said.

Kelley and Agranoff told the Union-Tribune that they didn't know who started the condominium fire and believed it would violate their free speech rights to be forced to testify about the speech.

Agranoff said he would testify in open court.

A third person who had refused to testify, Michael Cardenas, changed his mind and said he left before the part of the speech investigators are interested in came up.

Attorneys for the jailed activists said they would appeal.